Improvement in dowel-pins



B. F. ALLEN. DoweI-Pin.

No. 201,378. Patented March 19, l878..

WITNESSES mwma I $2 100 6% UNITED STATES PATENT OFFICE.

BENJAMIN ALLEN, OF BOSTON, MASSACHUSETTS.

lM PROVEM ENT IN DOWEL-PINS.

Specification forming part of Letters Patent No. 201,378, dated March19, 1878; application filed February 25, 1878.

To all whom it may concern Be it known that l, BENJAMIN F. ALLEN, ofBoston, in the county of Suffolk and State of Massachusetts, haveinvented certain new and useful Improvements in Dowel-Pins; and I dohereby declare that the followin g is a full, clear, and exactdescription of my invention, which will enable others skilled in the artto which it appertains to make and use the same, reference being had tothe accompanying drawings, and to letters of reference marked thereon,which form a part of this specification.

This invention relates to that class of devices used in joining two ormore pieces of wood or other material when it is desired to unite themby a firm and durable joint, as in the leaves and tops of tables,door-panels, I barrel-heads, boxes, and many other articles which arefrequently composed of more than one piece, and in which it is necessarythat the joining should have great strength, and not increase thethickness of the material; and the invention consists in theconstruction of a dowel-pin in such a manner that it may be completelyformed ready for use as an article of manufacture, and will expand whendriven into the holes made for its reception in the different pieces ofmaterial to be united, as will be hereinafter fully set forth.

In the drawings, Figure 1 is a perspective view of two pieces ofmaterial united by means of my improved joining, and then dividedlongitudinally through the middle, so as to show the relative positionsof the different parts of the dowel-pin after being driven into theholes formed for its reception. Fig. 2 is a side view of one of thedowel-pins with its retainingring and wedges. Fig. 3 is a longitudinalsection of the pin as shown in Fig. 1.

A and B represent two pieces of wood or other material, in each of whichhas been formed a hole, a, gradually increasing in its dimensions as itenters the parts, so that a diametrical section would exhibit a dovetailform, as shown in Fig. 1 of the drawings. A sufficient number of theseholes are formed in each part to give the desired strength to the jointwhen they are filled by the dowel-pins and the parts are broughttogether, either with or without the interposition of glue or othercementing material.

The dowel-pins are formed of two parts, I) b, each of which is ofsemicircular section, the two together forming a pin equal in diameterto that of the holes a at their narrowest part, the pin being encircledat or near the middle of its length by the ring 0, which retains the twohalves of the pin in juxtaposition while it is being inserted into theholes in the parts A B.

It is evident these rings may be of other ma terial than metal, if founddesirable, for, their function being principally the holding of theparts of the pin together until they are placed in position, no greatstrain comes upon them, and consequently any material capable of bearingthis slight strain will answer; but I prefer the metal ring constructedas shown in the drawing, as it is not only cheap, but efficient, notbeing afl'ected by variations of temperature or moisture to such anextent as in any way to impair its usefulness for this Purpose.

Two wedges, d d, are slightly inserted, one in each end of the pin, intothe diametrical cleft formed by the union of the two parts I) b, theslight expansion of these parts by the insertion of the wedges causingthem to fill the rings 0 tightly, and by their pressure upon the ends ofthe two wedges they are also held in place. 1

It will be apparent that dowel-pins formed in this way ready for use maybe placed upon the market for sale like any ordinary article ofmanufacture, and when applied to use are driven into holes formed in oneof the pieces which are to be fastened together. The wedge, striking thebottom of the hole, expands the end of the pin, causing it to fill thehole perfectly, and resist all efforts to extract it. The other piece tobe attached is then driven onto the pin or pins, one end of which hasalready been fixed, the wedge striking the bottom of the hole andexpanding the parts, as already stated. The ring 0 will occupy aposition at the junction of the two parts, and embed itself in them; or,if desired, a slight countersink may be made for its reception.

The dowel-pin having wedges inserted in a knife-cleft in its oppositeends for connecting two pieces of wood has long been in use; but theselacked the facility of construction by machinery so necessary to bringan article of this kind into general use.

Having thus described my invention, I claim as new and desire to secureby Letters Patent the following:

A dowel-pin composed of the two semicircular parts encircled. by a ringand provided at one or both ends with Wedges for the purpose of securingthe pin in an orifice into which it is driven, substantially asdescribed.

In testimony that I claim the foregoing as my own I hereunto affix mysignature in presence of two witnesses.

BENJAMIN F. ALLEN.

Witnesses:

J OSEPH CUTLER, J OHN G. JACKSON.

